Research On Impact Resistance And Temperature Characteristic For Quartz Flexible Accelerometer

As a representative of the high-precision inertial sensors,quartz flexible accelerometers(QFAs)have the characteristics of low cost,easy operation,simple structure,small mechanical and elastic hysteresis aftereffect,widely used in strapdown inertial navigation system.However,the QFA may work in severe environment,such as vibration,shock,temperature change,which will has great influence on its precision,stability and longevity.In this dissertation,the impact resistance and compensation technology of quartz flexible accelerometer have been studied by means of theoretical analysis and concrete test.The primary works are listed as follows:1.The impact resistance of the QFA has been analyzed and optimized.First,by the knowledge of mechanics of materials and the pendulous component model,this dissertation calculates the stiffness of the flexible beam,mechanical sensitivity,rotary inertia and the inherent frequency of the pendulous component,then by the modal analysis and transient dynamic analysis,this dissertation goes on a comparison of the impact resistant performance of pendulous component in input shaft,pendulum shaft and output shaft,to determine the maximum stress position of the flexible beam.Finally,the measures to improve QFAs' impact resistance performance are proposed from the aspects of material and structure.2.The temperature error model and compensation technique of the QFA have been studied.This paper first elaborates the mechanism of temperature error in detail,and introduces temperature test platform and the specific test methods,then in 1g gravity field,using 12 point rolling method and least square method to identify the static temperature error model,and finds the fitting formulas about partial value,scale factor with temperature.Finally,the output data is compensated.The results show that the precision has been increased.3.In order to improve the stability of the magnetic field in the air gap,the compensation ring of the torque has been analyzed and optimized in the structural level.Begins with a detailed introduction to every part of the torque,especially the structure and work principle of the compensation ring,then using finite element simulation to research the air gap magnetic field,to find out the optimal working position of the coil,and to reduce the measurement error.Then by controlling variables method and iterative method,this dissertation confirms the function of compensation ring,and finds out that the height is the key parameter of the compensation effect.Finally,combined with the specific test data,the size of the compensation ring is optimized.The research shows that on the condition of the fit size and optimal coil position,the temperature stability of the magnetic field has been greatly improved.